COMPOSITION CONTAINING 1,2-DIBROMO-2,4-DICYANOBUTANE (DBDCB) AND ZINC PYRITHIONE (ZPT)
20190269129 ยท 2019-09-05
Assignee
Inventors
Cpc classification
C09D5/14
CHEMISTRY; METALLURGY
International classification
Abstract
A composition, characterized in that it comprises 1,2-dibromo-2,4-dicyanobutane (DBDCB) and zinc pyrithione (ZPT) as active components.
Claims
1. A method for protecting water-containing functional liquids and water-containing industrial products from attack and/or destruction by bacteria and/or yeast, the method comprising the steps of: incorporating a biocide composition comprising active biocide component into the water-containing functional liquids and water-containing industrial products, wherein the active biocide component comprises 2-dibromo-2,4-dicyanobutane (DBDCB) and zinc pyrithione (ZPT) in a ratio of 10:1 to 1:10.
2. The method according to claim 1, wherein the active biocide component consists essentially of the 1,2-dibromo-2,4-dicyanobutane (DBDCB) and the zinc pyrithione (ZPT).
3. The method according to claim 1, wherein the biocide composition further comprises at least one further biocidal active substance, wherein the at least one further biocidal active substance is selected from the group of 1,2-benzisothiazol-3(2H)-one (BIT), iodopropargyl butylcarbamate (IPBC) and 2-n-octylisothiazolin-3-one (OIT).
4. The method according to claim 3, wherein the sum of DBDCB, ZPT and the at least one further biocidal active substance is 1 to 80 wt %, based on the total weight of the biocidal composition.
5. The method according to claim 3, wherein the biocide composition further comprises zinc oxide (ZnO), in a weight ratio of ZnO to the sum of the components DBDCB, ZPT and the at least one further biocidal active substance of 1:1 to 1:10.
6. The method according to claim 5, wherein the biocide composition further comprises 20 to 99 wt % of at least one auxiliary selected from the group consisting of surface-active substances, wetting agents, emulsifiers, dispersants, stabilizers, adhesives, thickeners, spreading agents, organic solvents, fragrances, colorants, antidusting agents, buffering substances, buffer systems, pH regulators, solid carriers and water.
7. The method according to claim 5, wherein the biocide composition further comprises 60 to 95 wt % at least one auxiliary selected from the group consisting of surface-active substances, wetting agents, emulsifiers, dispersants, stabilizers, adhesives, thickeners, spreading agents, organic solvents, fragrances, colorants, antidusting agents, buffering substances, buffer systems, pH regulators, solid carriers and water.
8. The method according to claim 1, wherein at least 60 wt % of the sum of the active components DBDCB and ZPT are present in the composition in dissolved form.
9. The method according to claim 1, wherein the biocide composition contains no further biocidal active substance, and the sum of the DBDCB and the ZPT is 1 to 80 wt %, based on the total weight of the composition.
10. The method according to claim 1, wherein the biocide composition further comprises zinc oxide, in a weight ratio of ZnO to the sum of the components DBDCB and ZPT of 1:1 to 1:10.
11. The method according to claim 1, wherein the 1,2-dibromo-2,4-dicyanobutane (DBDCB) and zinc pyrithione (ZPT) are present in synergistically effective amounts.
12. The method according to claim 1, wherein the DBDCB and the ZPT are present in the biocide composition at a weight ratio of DBDCB to ZPT of 4:1 to 1:4, and at least 95 wt % of the DBDCB and the ZPT are present in the biocide composition in dissolved form; wherein the biocide composition further comprises at least one of: at least one further biocidal active substance selected from the group consisting of 1,2-benzisothiazol-3(2H)-one (BIT), iodopropargyl butylcarbamate (IPBC) and 2-n-octylisothiazolin-3-one (OIT), such that the sum of DBDCB, ZPT and the at least one further biocidal active substance is 5 to 40 wt %, based on the total weight of the composition; and zinc oxide (ZnO), in a weight ratio of ZnO to the sum of the components DBDCB, ZPT and the at least one further biocidal active substance of 1:1 to 1:10; and the biocide composition is biocidally active against: Alcaligenes, Bacillus, Enterobacter, Escherichia, Proteus, Pseudomonas, Serratia, and Staphylococcus bacteria; Candida, Geotrichum, Rhodotorula, and Saccharomyces yeasts; and Acremonium, Alternaria, Aspergillus, Chaetomium, Fusarium, Lentinus, Paecilomyces, Penicillium, and Trichoderma fungi.
12. The method according to claim 1, wherein the biocide composition is present in relation to the product in an amount of 0.01 to 5 wt %, based on the weight of the product.
Description
EXAMPLES
[0111] The synergism of the composition according to the invention is demonstrated hereinbelow by way of example against certain germs that are particularly relevant in practice, for example Pseudomonas aeruginosa (example 1).
[0112] The observed synergism of the composition according to the invention may be determined by the following mathematical formula (cf. F. C. Kull, P. C. Elisman, H. D. Sylwestrowicz, P. K. Mayer, Appl. Microbiol. 9, p. 538 (1961):
[0113] where: [0114] Q.sub.a=the amount of component A in the active substance mixture which achieves the desired effect, i.e. no microbial growth, [0115] Q.sub.A=the amount of component A which, when used on its own, suppresses the growth of the microorganisms, [0116] Q.sub.b=the amount of component B in the active substance mixture which suppresses the growth of the microorganisms,
[0117] and [0118] Q.sub.B=the amount of component B which, when used on its own, suppresses the growth of the microorganisms.
[0119] A synergistic index obtained according to the above formula of SI<1 indicates a synergistic effect for the active substance mixture. The smaller the SI, the greater the synergistic effect.
[0120] The synergistic activity enhancement is elucidated by way of example but not by way of limitation with reference to the examples and calculations which follow.
Example 1: Synergism Toward Pseudomonas aeruginoasa
[0121] The minimum inhibitory concentration of the inventive compositions listed in table 1 were investigated using the test germ Pseudomonas aeruginoasa.
TABLE-US-00001 TABLE 1 no. DBDCB:ZPT DBDCB [ppm], Q.sub.a ZPT [ppm], Q.sub.b SI 1 8:2 200 50 0.91 2 6:4 45 30 0.68 3 5:5 37.5 37.5 0.65 4 4:6 30 45 0.72 5 2:8 10 40 0.57 6 1:9 7.5 67.5 0.93 (test germ: Pseudomonas aeruginosa, Q.sub.A = 250 ppm of DBDCB, Q.sub.B = 75 ppm of zinc pyrithione)
[0122] In certain concentration ratios the inventive compositions show a distinct synergistic effect against the test germ Pseudomonas aeruginoasa.
Example 2: Synergism Toward Enterobacter aerogenes
[0123] The minimum inhibitory concentration of the inventive compositions listed in table 2 were investigated using the test germ Enterobacter aerogenes.
TABLE-US-00002 TABLE 2 no. DBDCB:ZPT DBDCB [ppm], Q.sub.a ZPT [ppm], Q.sub.b SI 1 9:1 78 9 0.96 2 6:4 30 20 0.90 3 5:5 25 25 0.75 4 4:6 20 30 0.80 5 2:8 10 40 0.82 (test germ: Enterobacter aerogenes, Q.sub.A = 100 ppm of DBDCB, Q.sub.B = 50 ppm of zinc pyrithione)
[0124] In certain concentration ratios the inventive compositions show a distinct synergistic effect against the test germ Enterobacter aerogenes.
Example 3: Synergism Toward Rhodotorula mucilaginosa
[0125] The minimum inhibitory concentration of the inventive compositions listed in table 3 were investigated with the test germ Rhodotorula mucilaginosa.
TABLE-US-00003 TABLE 3 no. DBDCB:ZPT DBDCB [ppm], Q.sub.a ZPT [ppm], Q.sub.b SI 1 9:1 22.5 2.5 0.55 2 8:2 20 5 0.60 3 6:4 15 10 0.70 4 5:5 12.5 12.5 0.75 5 4:6 10 15 0.80 6 2:8 5 20 0.90 7 1:9 2.5 22.5 0.95 (test germ: Rhodotorula mucilaginosa, Q.sub.A = 50 ppm of DBDCB, Q.sub.B = 25 ppm of zinc pyrithione)
[0126] In certain concentration ratios the inventive compositions show a distinct synergistic effect against the test germ (yeast) Rhodotorula mucilaginosa.
Example 4: Microbiological Stress TestPreservation of a Polymer Emulsion
[0127] The preserving effect of an inventive composition comprising DBDCB and ZPT in a polymer emulsion (acrylate-based, pH=6.5) was investigated using a microbiological stress test.
[0128] The microbiological stress test examines the susceptibility of water-based systems to microbial attack and the effect of preservatives. To this end, the preservatives are incorporated in defined concentrations into the water-based systems. After the preparations have been completed, contamination with microorganisms of a defined type is effected at weekly intervals over a test period of 3 to not more than 6 weeks. 2-3 days and 7 days after each contamination, germ number determination is used to establish whether a complete kill or at least propagation inhibition of the introduced microorganisms compared to the unpreserved control samples has been achieved.
[0129] Having knowledge of the microorganism populations prevalent in polymer emulsions and dispersions the experiment employed a mixture of the following microorganism types for testing:
[0130] Bacteria: Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus.
[0131] Molds: Acremonium strictum, Aspergillus niger and Geotrichum candidu.
[0132] Yeasts: Candida albicans and Rhodotorula rubra.
[0133] Very good activity is achieved when the preserved samples achieve a complete kill (0 bacteria/mold/yeast cells per g) of the introduced microorganisms (score of 3=very good).
[0134] The effect is deemed good when compared to the unpreserved sample (so-called reference sample) a markedly reduced microbe level is observed (10.sup.310.sup.1 bacteria/10.sup.210.sup.1 mold/yeast cells per g) (score of 2=good).
[0135] The effect is deemed fair when compared to the unpreserved sample a mildly reduced microbe level is observed (10.sup.410.sup.3 bacteria/10.sup.310.sup.2 mold/yeast cells per g) (score of 1=fair).
[0136] The effect is deemed poor when compared to the unpreserved sample no reduction or only a minor reduction of the microbe level is observed (residual level of at least 10.sup.5 bacteria/10.sup.4 mold/yeast cells per g) (score of 0=poor). The results achieved are shown in table 4:
TABLE-US-00004 TABLE 4 Activity of the biocides determined 1 week after germ addition in each case Biocide added week week week [wt %] M week 1 week 2 week 3 4 5 6 0.025% DBDCB B 0 0 0 0 0 0 S 0 0 0 0 0 0 H 0 0 0 0 0 0 0.050% DBDCB B 0 0 0 0 0 0 S 0 0 0 0 0 0 H 0 0 0 0 0 0 0.05% ZPT B 0 0 0 0 0 0 S 2 2 2 2 2 2 H 2 2 2 2 2 2 0.01% DBDCB + B 2 2 2 2 2 2 0.01% ZPT S 2 2 2 2 2 2 H 2 2 2 2 2 2 (M = microorganism, B = bacteria, S = molds, H = yeasts)
[0137] Addition of an inventive composition comprising DBDCB and ZPT achieves effective preservation despite a markedly reduced active substance amount compared to the respective individual active substances, i.e. good activity is observed against all microorganism types employed for testing.